This summer, town hall meetings to discuss health care reform have turned into battlegrounds—with fist fights, belligerent protestors, and at least one lawmaker reporting a death threat. Some Democrats have blamed the chaos on astroturf operations: fake grassroots groups funded by special interests. But are the forces whipping up the anti-health care frenzy really astroturf—or a new form of corporate-funded campaigning?

Most astroturf operations are semi-covert activities, precisely targeted at vulnerable or undecided lawmakers. Tried-and-true practices include phone banks in which paid callers posing as concerned voters read from prepared scripts, or phony citizens groups with few members, if any, but plenty of industry money to bankroll television ads and mailers. Particularly unscrupulous operators might mobilize a narrow constituency—like conservative Christians—on behalf of their corporate clients. The idea is to create the impression of grassroots activism, but rarely to seriously attempt to influence broader public opinion. Michael Scanlon, a colleague of disgraced uberlobbyist Jack Abramoff, once captured the logic succinctly: "Simply put we want to bring out the wackos to vote against something and make sure the rest of the public lets the whole thing slip past them."

By that standard, some of the groups orchestrating town hall protests against Obama's health care reform have adopted a new, hybrid model—one that blurs the lines between astroturf and grassroots activism. As far as it's possible to tell, their financial base remains heavily dependent on corporate interests, and some of their tactics are familiar, too. But instead of furtively targeting selected lawmakers, they’re also mounting highly visible outreach efforts via public forums and Facebook, Twitter, and other social networking tools. In the process, they're picking up at least some genuine support. It remains to be seen whether they can attract large numbers to their cause, but already they've helped to hijack the health care debate at a critical juncture. Here's MoJo's guide to the major groups and their backers.

Americans for Prosperity is one of the most prominent groups opposing the Obama administration's two key domestic policy goals: health care reform and cap and trade. The organization presents itself as a grassroots movement that espouses limited government. But a large portion of its money comes via staunch free-market conservative David Koch, part owner of Koch Industries, an oil and gas conglomerate that is perhaps the largest privately owned company in the US, with holdings in medical device and pharmaceutical companies.

Koch helped found AFP in 2003 and serves as chairman of its affiliated foundation. Its president is Tim Phillips, a master of the art of astroturf. Along with Ralph Reed, he cofounded Century Strategies, a PR and consulting firm known for effectively renting out Reed's evangelical Christian allies to its clients—not to mention clients of Jack Abramoff. In 1999 and 2000, Century mobilized anti-gambling evangelicals to protest proposed casinos—but didn't know Century was working for an Abramoff client, a casino-owning Indian tribe hoping to vanquish its competition. In a memo, an Abramoff colleague noted that Century's Christian connections would ensure a "political effort that truly resembles a people's movement" without the signs of a "paid political operation."

This year, AFP is devoting its deep resources and strategic prowess to organize protests at Democratic health care town hall meetings, where activists hold signs like "Sorry Grandma, No Health Care for You." But unlike most typical astroturf operations, AFP's efforts seem intended to gather a broader base of supporters. To that end, the group makes use of social networking sites to reach out to potential followers. It posts information about local events and organizing strategies for its nearly 4,500 fans on Facebook, who share YouTube videos of protests. More than 1,000 people rallied at an August event in Scottsdale, Arizona, organized by AFP; the local fire department was called to handle overflow.

AFP sponsors two other groups advocating against the Obama administration's proposed reforms, innocuously titled Patients United Now and Patients First. Both fund ads that make misleading claims. One Patients United Now television ad wrongly asserts that "Washington wants to bring Canadian-style health care to the US." Patients First also launched a 13-state bus tour that wraps up at the end of August. At one stop a speaker compared proposed reforms to the Stalin and Hitler regimes because they would lead to "physician-assisted suicide"—a blatantly false claim. But these outlandish accusations have proved convincing to some: More than 206,000 people have signed Patients First's petition opposing current health care reform proposals.